Disposable garments are generally well known in the art and have become an important and an essentially indispensable sanitary protection item, most particularly in the field of infant and child care where disposable diapers provide for the absorption and containment of urine and other bodily exudates. Present commercially available disposable diapers are generally unitary, preshaped and prefolded, and comprised of a porous facing layer and a fluid impervious backing sheet with an absorbent material disposed therebetween. These presently available disposable diapers have met a particular need and have become ever increasingly popular. However, even though the present available disposable diapers have achieved a certain degree of efficiency and effectiveness, several draw-backs remain that have been identified by mothers of infants wearing the diapers. These mothers have strongly voiced their desire to be able to obtain disposable diapers that are aesthetically neat and attractive when on their infant or child. The aesthetically neat criteria have been identified as including a trim, slim fit, and a neat fitting waist and legs that do not allow leakage of urine or feces. It has also been found that mothers do not want their children looking rumpled, bulky or messy. In addition, these mothers have expressed the desire to either have a disposable diaper that fits more sizes of babies or to have disposable diapers provided in more sizes. Another draw-back identified by these mothers has been the problem associated with skin irritation caused by urine, feces or moisture trapped next to the skin. They have again been very vocal in their desire to obtain disposable diapers that avoid or solve this problem.
The typical disposable diaper has a three-layer composite structure comprising a liquid permeable bodyside inner liner, a liquid impermeable outer cover and an absorbent batt sandwiched between the liner and the cover. Materials now in general use for the three principal elements of a disposable diaper include various types of nonwoven fabrics for the bodyside liner, a thin thermoplastic film for the outer cover and cellulosic fluff for the absorbent batt.
Disposable diapers of the type presently on the market are flat open-sided garments that are intended to be fit around an infant by a parent while the infant is lying down. The rear panel of the diaper is placed underneath the infant, and the front panel drawn between the infant's legs, after which the sides are overlapped and held together by pressure-sensitive adhesive tape. A diaper is meant for use when the child is young and dependent upon a parent for this essential purpose. Examples of present disposable diapers are taught in U.S. Pat. No. 4,324,245 to Mesek, et al., U.S. Pat. No. 3,196,874 to Hrubecky, and U.S. Pat. No. 4,050,462 to Woon, et al.
Prior art diaper constructions disclosed in the references listed below have sought to provide waste containment with a reusable diaper holder receiving an absorbent structure:
1. U.S. Pat. No. 3,658,064 to Pociluyko and U.S. Pat. No. 3,370,590 to Hokanson, et al.;
2. U.S. Pat. No. 4,425,128 to Motomura;
3. U.S. Pat. No. 2,141,105;
4. U.S. Pat. No. 4,397,646 to Daniels, et al.;
5. U.S. Pat. Nos. 4,597,761, 4,496,360 and 4,597,760.
Other diapers, e.g., U.S. Pat. No. 4,166,464 to Korpman, have utilized elastic fluid impermeable backing films laminated to an absorbent layer in an attempt to provide enhanced conformability to the body surface.
U.S. Pat. Nos. 4,355,425 to Jones, et al. and 3,644,157 to Draper disclose disposable stretchable nonwoven panties unsuitable for absorbing and containing body wastes.
Even where prior art designs have attempted to use impermeable elastic film barriers, there has been inadequate recognition of the functional problems associated with an elastic outer cover. Further, costly woven diaper holders or overpants, designed to be waterproof and reusable, do not offer a truly disposable capability.
U.S. Pat. No. 4,610,681 to Strohbeen, et al., assigned to the instant assignee, the entire disclosure of which is incorporated by reference herein and relied upon, discloses a disposable underpant, such as a child's pull-on training pant, having a multi-layer web and sealed with exterior side seams. The training pant includes elasticized leg and waist openings but otherwise has nonelastomeric components. The side seams join together closed side panels of the pant, allowing the child to raise and lower the pant unassisted during toilet training. Should the pant "accidentally" become soiled, the side seams are manually separable to allow removal of the pant without requiring removal of any outer clothing from the child. The outer cover of the pant comprises a nonwoven material with a simulated cloth feel intended to further enhance the transition from infant diapers to reusable cloth underpants which are worn after the toilet training period.
U.S. Pat. Nos. 4,610,680 and 4,619,649 both disclose a training pant wherein a tear strand allows the pant to be separated for removal from the child when soiled. Likewise European Patent Application No. 0,048,011 A1, published Mar. 24, 1982, discloses a tear string allowing the panty to be separated for removal upon soiling.
Although the above-mentioned prior art diapers and training pants are provided with elasticized leg and/or waist openings, there is still a tendency for the garment to blouse outwardly from the body at the hip and lower abdominal regions. Thus, there remains a need for an anatomically form-fitting, generally self-adjusting training pant or other disposable underpant that may be worn and used unassisted, either by a child in toilet training or by an incontinent adult, and then easily removed when soiled without a mess.